In a wireless communication system, an eNodeB (eNB) assigns air interface resources to wireless transmit/receive units (WTRUs) for the transmission and reception of data. The eNB assigns resources and the associated parameters, (e.g., modulation and coding scheme), for transmission and reception of WTRUs so that the quality of service (QoS) requirements, (e.g., delay, packet error and loss rate, etc.), associated with the data for the WTRUs are met while maintaining fairness to other WTRUs and maximizing capacity, (i.e., the number of WTRUs it can serve).
WTRUs may provide the serving eNB with a WTRU buffer status report (BSR) which tells the eNB the amount of available uplink data stored in the WTRU uplink buffers that is ready for transmission and retransmission. The BSR is used for QoS-aware packet scheduling in the evolved UMTS terrestrial radio access network (E-UTRAN).
Radio bearers (RBs) may be assigned quality of service (QoS) parameters by the network. QoS parameters define service attributes such as type of service, delay tolerance, and data error and loss tolerance. A WTRU knowing the required QoS of its RBs may make intelligent decisions on how to prioritize the RBs with respect to which data to choose to transmit when resources are assigned. The eNB may use this information to assign resources to WTRUs and prioritize transmission such that each individual WTRU performance and throughput requirements are as closely met as possible.
A QoS class identifier (QCI) may be used to define the QoS. Table 1 shows QCI characteristics including a resource type, a priority, a packet delay budget, and a packet error and loss rate. Table 2 shows a mapping of the traffic classes to the QCIs.
TABLE 1PacketRe-PacketErrorsourcePrior-DelayLossQCITypeityBudgetRateExample Services1GBR2100 ms10−2Conversational voice24150 ms10−3Conversational video (live streaming)33 50 ms10−3Real time gaming45300 ms10−6Non-conversational video(buffered streaming)5Non-1100 ms10−6IMS signallingGBR66300 ms10−6Video (Buffered Streaming),TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressivevideo, etc.)77100 ms10−3Voice, Video (live streaming),interactive gaming88300 ms10−6Video (buffered streaming), 99TCP-based (e.g., www, e-mail, chat, ftp, p2pfile sharing, progressive video, etc.)
TABLE 2TrafficSourceTrafficHandlingSignallingStatisticsQCIClassPriorityIndicationDescriptor1ConversationalN/AN/ASpeech2ConversationalN/AN/AUnknown3ConversationalN/AN/AUnknown4StreamingN/AN/AUnknown5Interactive1YesN/A6Interactive1NoN/A7Interactive2NoN/A8Interactive3NoN/A9BackgroundN/AN/AN/A